This invention pertains to plumbing equipment and, more particularly, to fittings for use with hot water heaters and other appliances.
Various types of storage water heaters are in common use. Typically, storage water heaters include a tank connected with a source of cold water supply, such as, for instance, a city water main, a gas burner or an electric heating element positioned adjacent the tank to heat the water, and a conductive connection between the tank and the hot water distributing system. Storage water heaters are used in private homes, condominiums, apartments, hotels and other places where a steady source of hot water is desired.
It has been long been known that when a storage water heater tank of this type is connected with a city water main, electrolytic decomposition of the tank can occur. This is primarily due to the fact that there are different kinds of metals present in the assembly, i.e., the tank may be made of iron and the pipe line connection may be galvanized iron, copper or brass.
It is often the practice to pass the cold water supply in through the top of a water heater tank by extending the tube or pipe that conducts the water, down through the tank and discharging hot water through an outlet line connected to the tank. In such an unit, if the downwardly extending pipe within the tank is a metallic electrical conductor and the tank itself is metal of a different kind, which is often the situation, then galvanic action can occur, particularly when the water in the tank is heated. This galvanic action creates electrical currents which are considerably stimulated by the fact that the incoming water pipe serves as an excellent ground for the unit. Such electrical currents tend to decompose the metal of the tank and other associated parts and fittings, with the result that leaks may develop and the tank eventually may have to be replaced or repaired.
Also, during decomposition of the metal of the tank, electrical currents tend to decompose the water in the tank, liberating oxygen which often oxidizes and corrodes the tank and associated fittings.
Presently, standard hot water heaters have a threaded female opening, such as a 3/4 inch pipe thread. A flexible tube is connected to the water heater, but the end of the flexible tube also has a threaded female opening, such as a 3/4 inch pipe thread. The flexible tube is connected to the hot water heater by a male nipple, such as with a 3/4 inch male pipe thread at one end which is connected to the water heater and another 3/4 inch male pipe thread at the opposite end which is connected to the flexible tubing. The plumbing codes for many states provide that there must be a dielectric break, which is something in the fitting to break the union between two unlike metals thereby preventing corrosion. The dielectric break for prior art is a plastic insert of plastic molding that is inserted and is not removable.
In the past, hot water heaters, sinks, wash basins, and other appliances were installed, by using a rigid pipe such as a copper pipe which was suitably bent for attachment to the end of a water distribution pipe and the water supply intake of the appliance. The plumber or other installer had to make precise measurements, cut the copper pipe accordingly, shape it and finally connect it by welding. Such tasks were burdensome, cumbersome, and slow and not readily adaptable for do-it-yourself amateurs and most homeowners.
Flexible pipes have been used for connecting appliances to a distribution network. Conventional flexible pipes have a copper tubular structure comprising corrugated walls which enable the pipe to be manually bent to the position of the fluid intake on the appliance as well as to the end of the distribution pipe. However, in order to be flexible, this type of tube has an extremely thin fragile metallic wall, which often cracks upon repetitive bending or flexing. Such cracks cause water leaks from the pipe.
The connections of appliances supplied with water using conventional metal or flexible metal pipes often transmit vibrations from the appliance.
Conventional corrugated flexible pipes have corrugated tubes and were introduced after the rigid pipe. Corrugated flexible pipes allow some degree of flexibility during installation. The body of the flexible pipe allowed some flexibility, but still many homeowners had trouble doing-it-themselves. If the corrugated flexible pipe is bent into one position, then bent again to correct a mistake in the alignment, it work-hardens the tubing. Usually, two or three bends work-hardens the tubing to its failure point. The corrugated flexible pipe often splits and forms a hole between one or more of its corrugations causing water leaks.
Conventional corrugated flexible pipes also create a great deal of turbulence in the fluid it conveys. The turbulence is caused by the corrugations of the pipe. The turbulence can decrease flow rates drastically and can also be a source of water flow noise. This noise can also be transmitted throughout the piping network.
Although a hose can be longitudinally extensible for accommodating an internal excess pressure, the flow rate will be reduced if the diameter is decreased. It is important that the flow rate be uniform. It is, therefore, desirable that a connection of this type be dimensionally stable, irrespective of the internal pressure.
Over the years various types of hoses, pipe unions, and other connectors have been suggested. Typifying these prior art hoses, pipe unions, and other connectors are those shown in U.S. Pat. Nos. 299,206; 2,257,385; 3,501,171; 3,756,628; 4,083,583; 4,159,027; 4,595,218; 4,605,248; and Re. 25,407. These prior art hoses, pipe unions, and other connectors have met with varying degrees of success.
It is, therefore, desirable to provide an improved connector assembly which overcomes most, if not all, of the preceding problems.